Absorbent articles such as diapers, training pants, incontinence products, feminine hygiene products, swim undergarments, and the like conventionally include a liquid permeable body-side liner, a liquid impermeable outer cover, and an absorbent core. The absorbent core is typically located in between the outer cover and the liner for taking in and retaining liquids (e.g., urine) exuded by the wearer.
The absorbent core can be made of, for instance, super absorbent particles. Many absorbent particles, especially those sold under the tradename HUGGIES™ by the Kimberly-Clark Corporation, are so efficient at absorbing liquids that it is sometimes difficult to tell whether or not the absorbent article has been insulted with a body fluid.
Accordingly, various types of moisture or wetness indicators have been suggested for use in absorbent articles. The wetness indicators may include alarm devices that are designed to assist parents or attendants identify a wet diaper condition early on. The devices produce either a visual or an audible signal.
In some embodiments, for instance, conductive threads or foils have been placed in the absorbent articles in the machine direction. The conductive materials serve as conductive leads for a signaling device and form an open circuit in the article that can be closed when a body fluid, such as urine, closes the circuit. Incorporating a wetness sensing system into an absorbent article during its manufacture, however, can be problematic. For instance, many absorbent articles are made at relatively high speeds. At such speeds it can be difficult to not only incorporate a wetness sensing system into the absorbent article, but to ensure that the conductive leads are positioned properly. Thus, a need currently exists for a quality control process that can be used to verify that the absorbent articles contain a desired component or item, such as the metallic conductive leads of a wetness sensing system.